(NaturalNews) The intravenous administration of magnesium sulfate to a mother during premature labor can reduce her child's risk of developing cerebral palsy by 50 percent, researchers have found.

"This is one of the most promising breakthroughs in the management of high-risk pregnancies in more than 30 years," study co-author John Thorp said.

Cerebral palsy is a blanket term for a variety of movement and posture disorders caused by damage to the developing brain. Approximately one-third of all cases are linked to brain damage caused during premature birth - defined as occurring before the 32nd week of pregnancy.

Magnesium sulfate, also known as Epsom salt, is a chemical compound with a wide variety of medical uses. While it cannot prevent the onset of premature birth, it is well known to help regulate maternal blood pressure.

Prior studies on the compound's use in preventing cerebral palsy had been mixed, so researchers from the University of Alabama-Birmingham and the University of North Carolina-Chapel Hill designed and conducted the largest study to date to investigate the question. The study was funded by a grant from the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development, presented at the January meeting of the Society for Maternal-Fetal Medicine in Dallas and published in the New England Journal of Medicine.

Researchers treated 2,241 women at risk of preterm delivery with either magnesium sulfate or a placebo, in a study taking place at 20 different locations across the United States. All study participants went into labor between the 24th and 31st week of pregnancy. Magnesium sulfate was administered by means of a 6-gram intravenous dose at the onset of labor, followed by 2 grams per hour until 12 hours had passed or the labor had subsided or concluded. The children delivered from these pregnancies were then observed for another two years.

While there was no significant difference in the death rates of the children from the two groups, the rates of cerebral palsy were strikingly different. A total of 3.9 percent of children from the placebo mothers had developed cerebral palsy by their second birthday, compared with only 1.9 percent of children from the magnesium sulfate group. This translated to a 50 percent lower risk in the magnesium sulfate group.

The researchers emphasized that study's findings only apply to premature births, but said that the observed effect was large enough to warrant immediate implementation. In addition, he study's results were consistent with those of the second largest study ever conducted, a 2003 trial from Australia.

"If deemed to be at high or immediate risk of delivery prior to 32 weeks, women and their doctors should consider using magnesium sulfate to prevent their child from having cerebral palsy," lead author Dwight J. Rouse said.

No FDA approval is required for a new use of magnesium sulfate, Thorp noted.

"Virtually every delivery room in the United States is already stocked with magnesium sulfate solutions that are given to pregnant women during childbirth for other reasons," he said. "So what we have learned from this study is that we have a cheap, widely available treatment already in hand that cuts in half the risk of babies being born with an extremely disabling disorder. That is a tremendously exciting development."

Scientists remain uncertain exactly how magnesium sulfate acts to reduce cerebral palsy risk. They have speculated that it might protect a fetus from injury or damage caused by inflammation, swelling, or lack of oxygen, or that it might "stabilize the vessels in the vulnerable preterm brain."

No serious side effects were observed among women given magnesium sulfate, although some did experience blurred vision, sweating or flushing.